Shut-off fitting

ABSTRACT

A shut-off instrument for a flow medium, in particular a slide valve instrument designed for pressurization on both sides with an instrument housing forming a flow channel and a slide valve chamber and with a soft-sealing shut-off element closing off the flow channel and with a slide valve stem which penetrates a seal arrangement and/or bearing arrangement in a housing neck extension delimiting the slide valve chamber and which is rotationally connected to a stem nut coupled to the shut-off element by a screw contact. The shut-off element is designed to include more than one part and at least one external dimension of the main body is slightly smaller than a nominal width of the flow channel and seal elements are arranged on opposite support surfaces of the main body via an engaged connection projecting over the external dimension with a peripheral edge collar.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and Applicants claim priority under35 U.S.C. §§ 120 and 121 of parent U.S. patent application Ser. No.10/519,288, filed Aug. 23, 2005 now U.S. Pat. No 7,448,595. Applicantsclaim priority under 35 U.S.C. §119 of Austrian Application No. A966/2002 filed Jun. 27, 2002. Applicant also claims priority under 35U.S.C. §365 of PCT/AT03/00163 filed Jun. 4, 2003. The internationalapplication under PCT article 21(2) was not published in English.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a shut-off instrument for a flow medium.

2. Description of the Related Art

From the document DE 1 093 634 a shut-off valve is known with ashutting-off element comprising a carrier and a casing made of elasticmaterial. The shutting-off element encased with elastic material is inthe form of a hollow cylinder that is closed on one side in the form ofa spherical indentation, which cylinder is provided on its outer surfacewith the casing made of elastic material, and is adjustable from aposition of blocking the flow channel of a valve housing into a positionof opening the flow channel. This performed by means of a threaded stemmounted rotatably and sealingly in a neck extension of the valvehousing, the thread of which engages with an internal thread in theshutting-off element. The elastic casing forms, together withdiametrically opposite guide tracks and guide grooves receiving thelatter in the housing in a plane perpendicular to the flow direction, alinear guide for the positioning of the shutting-off element so that thelatter cannot rotate and is supported against the pressure of themedium. The stem bearing in the neck extension makes a pendulum movementof the adjusting stem possible by means of an elastic bearing andsealing element to obtain a sealed bearing on sealing surfacessurrounding the flow channel.

From a further document DE 527 748 a sealing device is known for asealing body of a stopcock or valve or slide valve, in which the sealingbody comprises a hollow cylindrical main body closed at one end and,which is provided on the cylindrical outer surface with a casing made ofelastic material for sealing arrangement in a housing shaping of a valvehousing forming the flow channel. The adjustment of the sealing body isperformed by an adjusting stem in a vertical direction determined by theflow direction in the flow channel, whereby the sealing body is providedwith diametrically opposite guide wings which engage in linear guidegrooves of a neck extension, and thus there is no risk of twisting andguiding. In order to avoid deformations to the hollow cylindricalsealing body caused by the pressure of the medium, bores traversing thecasing and walls of the sealing element are provided which equalize thepressure.

A method for producing a shut-off instrument and a shut-off element areknown from DE 19 16 347 A1, which comprises a one piece element housingwith a housing part forming a flow channel and a housing extension whichforms a slide valve chamber for a wedge-type valve and a stem bushingwith sealing arrangement and is joined in one piece to the housing part,for completely mounting a shut-off element designed with the slide valvestem movable as a wedge-type valve, which is guided in the elementhousing in such a way that it cannot be twisted. The design relates to aso-called hard sealing slide valve instrument and sealing elementsforming sealing surfaces opposite the flow channel are arranged, towhich diametrically opposed sealing faces on the wedge-type valve areallocated. In order to manufacture a one piece housing for a shut-offinstrument of this kind an expensive mould structure and mouldingprocedure is necessary, in order to position the premanufacturedwedge-type valve into a mould core and position it with the latter in acasting mould.

Furthermore, a shut-off instrument with a housing that is essentially inone piece is also known from DE 33 02 979 A1, which is provided with alateral assembly opening for inserting the shut-off instrument and thebearing arrangement, and which can be sealed with a housing lid. Inorder to achieve the required tightness, in particular at higher nominalpressures, it is necessary to shape the housing and the housing lid onthe sealing surfaces and design the securing of the housing lid in aparticular way.

SUMMARY OF THE INVENTION

The objective of the invention is to create a shut-off instrumentregardless of the design as a one-piece or multipart housing, by meansof the entire range of occurring pressure can be controlled, and due tothe simple installation of elements of the instrument made frommaterials adapted to the properties of the medium to be controlled, theshut-off instrument can be used universally.

The objective of the invention is achieved by a shut-off instrumentwherein the shut-off element includes multiple parts and at least oneexternal dimension of the main body is slightly smaller than a nominalwidth of the flow channel and seal elements are arranged on oppositesupport surfaces of the main body via an engaged connection projectingover the external dimension with a peripheral edge collar. The advantageof the design according to the invention is that the components formingthe shut-off element, comprising a main body, sealing elements and ifrequired support and securing means, are inserted through the flowchannel in operative position into the instrument housing, the main bodycan be coupled with the stem nut and the shut-off element can becompleted in assembly stages, without expensive assembly aids beingnecessary.

In another embodiment, sealing surfaces are arranged in the housing neckextension, which mount the sealing and/or bearing arrangement and areconcentric to a longitudinal muddle axis of the slide valve stem, whichseal surfaces widen conically from a base of the housing neck extensionin the direction of an end face of the housing neck extension. Thisembodiment is also advantageous however, because thereby the instrumenthousing is manufactured in such a way that the components for the sealand bearing arrangement can be assembled in the region of the slidevalve stem bushing without remachining.

In another embodiment, the instrument housing is in one piece with thehousing neck extension. This embodiment is advantageous, as thereby thebearing of the prefabricated components needed for the final assembly issimplified due to the low number of parts, and due to the short assemblytime the instrument can be assembled only to fulfil the orders actuallyreceived.

In another embodiment, the instrument housing includes multiple partswith the housing neck extension. This embodiment is also advantageous,as thereby simplified production methods can be applied formanufacturing the instrument housing.

According to further embodiments it is possible to provide in each casea housing division suitable for a specific purpose of the shut-offinstrument.

In another embodiment, the housing parts of the instrument housing aredetachably connected by a flange arrangement formed in a region of adivision plane. According to this embodiment the housing parts ofmulti-part housings can be sufficiently and reliably joined togethereven for high-pressure ranges.

According to further embodiments a torque applied by the adjustment ofthe shut-off element by the slide valve stem is taken up by the guidesof the stem nuts, and thereby the shut-off element, in particular thesealing elements of the shut-off element, is protected effectively fromasymmetrical loading and thereby uneven wear and damage.

According to further embodiments, a simple coupling procedure isachieved for producing the moving connection between the stem nut andthe main body of the shut-off element during assembly, in particular ina design of the shut-off element with a one-piece instrument housing.

In another embodiment, the main body is in the shape of a disc and inthe direction of an external dimension is penetrated by a mounting borereceiving the slide valve stem. According to this embodiment, acomponent that is simple to manufacture is obtained for the main body ofthe shut-off element.

In further embodiments particularly for greater nominal widths, such asfor example over 100 mm, the structure of the shut-off element issimplified and the assembly within a one-piece housing is facilitated.

In further embodiments, the pressure acting on the shut-off element isabsorbed by the medium in the guiding arrangement and kept apart fromthe slide valve stem and the smooth adjustment of the shut-off elementis ensured. The arrangement of guide elements in the main body, whichproject over the external dimensions of the latter in the region of themiddle axis, is particularly advantageous, because thereby there is asymmetrical removal of pressure into the guiding arrangement.

A one-piece structure of the main body with the guiding elements ishowever also possible, because in this way the assembly is simplified.

In another embodiment, the seal elements are connected with the supportdiscs and the guide elements preferably by securing means, e.g. a spacerscrew, arranged in a main body middle plane running perpendicular to thelongitudinal middle axis. This embodiment is advantageous becausethereby the completion of the shut-off element is simplified by assemblyof the sealing elements in the coupled state of the main body with thestem nut, i.e. in the region of the instrument housing.

According to further embodiments the leakage of medium through theshut-off element is effectively prevented in the shut position.

In further embodiments, a reliable and easily assembled sealingarrangement is achieved in the region of the slide valve stem bushingeven at the highest pressures.

In a further embodiment, the bayonet locking device of the seal carrierin the housing neck extension is formed by locking elements projectingdiametrically over an external diameter of the seal carrier and mountinggrooves allocated to the locking elements in a mounting bore of thehousing neck extension. In this embodiment, additional securing elementscan be dispensed with and assembly is simplified.

In a further embodiment, the seal carrier in the housing neck extensionis prevented from twisting by at least one flanged nose. This embodimentprevents rotation and thereby prevents the unintentional detachment ofthe seal carrier from the housing neck extension.

According to further embodiments, a particularly smooth bearing of theslide valve stem taking up radial and axial loads is achieved, wherebythe smoothness of the adjustment is ensured.

In a further embodiment, bearing means of the bearing arrangement forthe slide valve stem are formed by a bearing layer applied to bearingpoints in the housing neck extension. Thereby, the bearing elements canbe dispensed with, e.g. by sealing a bearing gap with a hardeningplastic composition suitable for bearing purposes.

In another embodiment, a neck ring is arranged at the end section of thehousing neck extension enclosing the stem projection, which is securedin the housing neck extension and penetrated by the stem projection.According to this embodiment a reliable, sealing housing neck seal isachieved, which is simple to assemble and disassemble, whereby themaintenance work and replacement of the seals or bearing elements aresimplified.

According to further embodiments, a versatile shut-off instrument ismade possible by using a combination of various different materials forthe individual elements of the shut-off instrument and the instrumenthousing, whereby the shut-off instrument can be used in low pressureconditions up to high pressure conditions, and for media of all kindsincluding highly aggressive media and within a broad temperature range.

In another embodiment, the locking position of the shut-off element, inwhich the seal elements lie against the sealing surfaces of theinstrument housing, is formed by a stop arrangement between the slidevalve stem and the main body of the shut-off element, in particular by adetent ring secured to the end section of the slide valve stem, whichdelimits the movement of the threaded stem. This embodiment ensurespressure equalisation and a reliable seal by preventing excess pressureon the seal elements to obtain even pressure on the sealing surfaces,whereby premature wear or damage to the seal elements is effectivelyprevented.

In another embodiment, the edge collar of the sealing element hassealing lips. In this embodiment, a multiple sealing effect and greaterelasticity of the seal elements are achieved in the bearing region, andthereby fewer elastic materials need to be used, which are advantageousfor many purposes, and a greater service life can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention the latter is explained inmore detail by way of the embodiments illustrated in the figures. Ofthese:

FIG. 1 shows a shut-off instrument in cross section along the line I-Iof FIG. 2;

FIG. 2 shows the shut-off instrument, in cross section along the lineII-II of FIG. 1;

FIG. 3 shows the shut-off instrument, in cross section along the lineIII-III of FIG. 1;

FIG. 4 shows the embodiment of the shut-off instrument of FIG. 1 incross section with the shut-off element positioned completely inside theslide valve chamber and showing in dashed lines a variant of theinstrument housing;

FIG. 5 shows the shut-off instrument according to the invention with adivided housing, in simplified view;

FIG. 6 shows a further design of a divided instrument housing insimplified view;

FIG. 7 shows a further design of a divided instrument housing insimplified view;

FIG. 8 shows a variant of a coupling arrangement in detail with theshut-off element and the stem nut, partially in cross section;

FIG. 9 shows the coupling arrangement in cross section along the lineIX-IX of FIG. 8;

FIG. 10 shows a further design of the instrument housing with a guidingarrangement for the shut-off element in plan view of a housing halfsection;

FIG. 11 shows a further design of the shut-off instrument according tothe invention in cross section along the line XI-XI of FIG. 12;

FIG. 12 shows the shut-off instrument in cross section along the lineXII-XII of FIG. 11;

FIG. 13 shows a further design of the shut-off element according to theinvention in cross section;

FIG. 14 shows a detail of the shut-off element in cross section alongthe line XIV-XIV of FIG. 13.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Firstly, it should be noted that in the variously described embodimentsthe same parts are allocated with the same reference numbers or the samecomponent names, whereby the disclosures contained throughout thedescription can be applied analogously to the same parts with the samereference numbers or the same component names. In addition, the detailsrelating to position such as e.g. top, bottom, side etc. relate to theFigure actually being described and when there is a change in positionshould be transposed to the new position. Furthermore, individualfeatures or combinations of features from the shown and describedvarious embodiments can in themselves represent independent, inventivesolutions according to the invention.

In FIGS. 1 and 2 a shut-off instrument 1, in particular a slide valveinstrument 2 is shown. The latter comprises an instrument housing 3which surrounds a flow channel 6 for a medium—arrow 7—between spacedapart connection elements 4, in the shown embodiment connection flanges5. The flow cross section 8 is a nominal width 9 of the flow channel 6.Furthermore, the instrument housing 3 with a housing projection 10 formsa slide valve chamber 11 and in an adjoining housing neck extension 12forms a stem bushing 13 with a seal arrangement 14 and a bearingarrangement 15 for a slide valve stem 16. The slide valve stem 16projects with a stem projection 17 through the housing neck extension 12into the slide valve chamber 11 and in the region of the slide valvechamber 11 comprises an external thread 18 with which a stem nut 19 withan internal thread 21 arranged inside a bore 20 is engaged. The stem nut19 is detachably connected via a detachable coupling arrangement 22 to ashut-off element 23.

A longitudinal middle axis 24 of the housing projection 10, housing neckextension 12 and the slide valve stem 16 is perpendicular to a middleaxis 25 of the flow channel 6.

The slide valve chamber 11 formed by the housing projection 10 has alength 26 in the direction of a longitudinal extension which is designedfor the complete clearance of the flow cross section 8 by the shut-offelement 23, and corresponds roughly to the nominal width 9 in additionto the height 27 of the stem nut 19.

The shut-off element 23 is in the form of a disc-shaped main body 28with an external dimension 29 which is slightly less than the nominalwidth 9. Facing the stem nut 19 the main body 28 comprises couplinggrooves 30 for the engagement of hoe-like coupling means 31 of the stemnut 19, whereby the detachable coupling arrangement 22 is formed betweenthe stem nut 19 and the main body 28 of the shut-off element 23.

Opposite bearing surfaces 32 of the main body 28 have a structure in theform of ribs 33 and on said bearing surfaces 32, disc-like so-calledsoft sealing elements 34 are arranged with a compatibly designedstructure, to form an interlocking arrangement. Said sealing elements 34have a circumferential edge collar 35, whereby the external dimension 36is greater than the nominal width 9, and are provided for the sealingarrangement on opposite sealing surfaces 38 formed by a housing shaping37.

In order to support the sealing elements 34 and secure them to the mainbody 28 support discs 40 arranged on opposite end faces 39 of the sealelements 34 are provided, which are secured by securing means 41, e.g.thread bolts 43 and thread nuts 44 traversing the main body 28, thesealing elements 34 and the support sheets 40 in bores 42.

It should also be mentioned that the main body 28 concentric to thelongitudinal middle axis 24 is provided with a mounting bore 45extending over the entire diameter 29 for feeding through the slidevalve stem 16, whereby the internal diameter 46 is slightly greater thanthe thread external diameter 47 of the slide valve stem 16.

The flow channel is designed to have preferably a circular flow crosssection 8 and on both sides of the shut-off element 23 flow channelsections are in alignment with one another and have an even flow crosssection 8. In a design of this kind the nominal width 9 corresponds to anominal diameter of the flow channel 6 and the external dimension 29 ofthe main body 28 corresponds to an external diameter.

The flow channel 6 can also have a different geometric shape, such asfor example an oval or elliptical shape.

According to the invention it is essential for the external dimension 29of the main body 28, with the round shape diameter, to be slightlysmaller than the nominal width 9 corresponding to a nominal diameter ofthe flow channel 6.

With an oval or elliptical shape it is essential according to theinvention to make the smallest external dimension 29 of the main bodyslightly smaller than the minimal size of the nominal width 9 of theflow cross section 8.

Said allowances considerably simplify the insertion of the main body 28,coupling with the stem nut 19 and assembly of the seal elements 34 in aone-piece instrument housing 3, whereby assembly aids can be dispensedwith and assembly time is saved.

In the region of the opposite housing shapings 37 in the centre of amiddle distance 48 between the sealing surfaces 38, guide webs 49projecting in the direction of the main body 28 are formed with aroughly triangular cross section, which run up to the region of theslide valve chamber 11, which cooperate with guide elements 50 fixed inthe main body 28 and projecting over its diameter 29 in the direction ofthe guide webs 49, whereby a linear guide arrangement 51 is obtained aswell as means for preventing the twisting of the stop element 23. Aclear space 52 between the guide webs 49 is equal to or slightly greaterthan the nominal width 9. The guide elements 50 are arranged for examplein slot-shaped recesses 53 of the main body 28 and fixed in the recess53 by securing means 41 traversing the main body 28. Preferably, theguide elements 50 are formed by pairs of guide sheets 54, which areangled in the projecting section, which surround the guide webs 49 in aV-shape.

The shut-off element 23 is activated, as already described above, bymeans of the stem nut 19 coupled by the coupling arrangement 22 to theshut-off element 23, the stem nut engaging with the external tread 18 ofthe slide valve stem 16. Furthermore, the stem nut 19 is guidedadjustably unable to be twisted in the slide valve chamber 11 in thedirection of movement according to double arrow 55. In addition, guides56 are arranged in the housing projection 10 which are diametricallyopposite in relation to the longitudinal middle axis 24 and run parallelto the longitudinal middle axis 24, in which guides the guide extensionsof the stem nut 19 engage. In this way a linear movement of the stem nut19 and thereby the shut-off element 23 is achieved on the basis of arotational movement of the slide valve stem 16 rotatably mounted in thehousing neck extension 12.

In the housing neck extension 12 in the bearing arrangement 15 the slidevalve stem 16 is rotatably mounted by a peripheral bearing collar 57 ina bearing sleeve 59 arranged in the housing neck top 12 and providedwith a bearing flange 58. On the upper side of the bearing collar 57opposite the bearing flange 58 a further face seal ring 60 is arranged,which is positioned against the bearing collar 57 by means of a sealcarrier 61 inserted in the housing neck extension 12 into the stembushing 13 and surrounding the stem projection 17. This design of thebearing arrangement 15 ensures the play-free, radial and axial bearingof the slide valve stem 16 in the housing neck extension 12.

The seal carrier 61 comprises an O-ring 64 in a bore 32 for the stemprojection 17 in at least one peripheral groove 63, whereby preferably afurther O-ring is arranged in a groove spaced further apart to decreasethe likelihood of leakage. Furthermore, the seal arrangement 14comprises a seal to prevent the leakage of the medium at a certainpressure level, which is preferably in the form of a pair of O-rings 65arranged between an external circumference 66 of the seal carrier 61 anda mounting bore 67 of the housing neck extension 12. A bearing bore 69facing the seal carrier 61 mounting the inner surface 68 of the mountingbore 67 as well as the bearing sleeve 59 runs from an end face 70 of thehousing neck extension 12 in the direction of the slide valve chamber 11corresponding to a surface of a conical casing, the lines of which runtogether in the direction of the slide valve chamber 11. The sealcarrier 61 is also designed to have a truncated-cone shaped surface atleast in the region of a seal projection. In this way with a one-piecedesign of the instrument housing 3 a cast design with the lowestmanufacturing tolerances is achieved, by means of which subsequent,expensive manufacturing procedures, such as e.g. a metal-removingrotatory procedure in the region of the stem bushing 13 becomesunnecessary, which results in considerable economic savings, and alsomeans that the parts are of the highest quality in terms of sealtightness and replaceability.

For the axial securing of the seal carrier 61 a neck ring 73 is providedsurrounding the stem projection 17 in an annular recess 71 of thehousing neck extension 12 and the seal carrier 61 with support surfaces72, which neck ring is locked e.g. by a locking arrangement 74 formed byhoe-shaped spring arms 75 in locking mounts 76 of the housing neckextension 12.

A preferred design of the seal carrier 61 and the mount 68 isillustrated in FIG. 3. According to this design the seal carrier 61comprises locking elements 77 which are diametrically opposite oneanother in relation to the longitudinal middle axis 24 and projectbeyond the external circumference 66. The mount 68 for the seal carrier61 comprises mounting grooves 78 for mounting the locking elements 77which face the latter in a locked position. The locking elements 77 andthe mounting grooves 78 extend respectively over a quarter of thecircular circumference of the external circumference 66 of the sealcarrier 61 and the mount 68 in the housing neck extension 12. In thisway a bayonet type of locking of the seal carrier 61 in the housing neckextension 12 is achieved and a position is reached at which the O-rings65 of the seal arrangement 14 are preloaded due to the conicity of themount 68.

The seal carrier 61 is shown in its locked position in the housing neckextension 12. In order to insert the seal carrier 61 during assembly orto remove it, e.g. for maintenance work, in particular when replacingthe O-rings, the seal carrier is rotated from the shown position into aposition pivoted about 90°, whereby the locking elements 77 aredisengaged from the mounting grooves 78 and the seal carrier 61 can beremoved from the mounting bores 67. The installation is performed in theopposite manner.

In FIG. 4 the shut-off instrument 1 is shown with the shut-off element23 with an open flow channel 6, whereby the shut-off element 23 ispositioned completely inside the slide valve chamber 11. In this case,the slide valve stem 16 in the region of the external thread 18penetrates the main body 28 of the shut-off element 23 completely aftera linear movement of the stem nut 19 according to arrow 79, when theslide valve stem 16 is opened at the stem projection 17. This kind ofactivation can be achieved manually by a hand wheel 80 engaging directlyon the stem projection 17 but in the case of an automated shut-offinstrument 1 by means of a motor drive, e.g. electric drive, compressedair drive etc.

In order to restrict the adjustment a stop arrangement 81 for example isprovided between the slide valve stem 16 and the shut-off element 23,e.g. a detent disc 83 positioned at an end region 82 of the slide valvestem 16, said detent disc being fixed onto the slide valve stem 16 bymeans of a securing nut 84 and forming a stop plane 85 perpendicular tothe longitudinal middle axis 24 for a lower side 86 of the main body 28.In this way a reliable end stop is obtained in the closed position ofthe shut-off element 23.

Furthermore, in FIG. 4 a possible variant of the design of theinstrument housing 3 is shown by dashed lines. According to this variantthe housing neck extension 12 forming the stem bushing 13 with the sealarrangement 14 and the bearing arrangement 15 is secured to the housingprojection 10 forming the slide valve chamber 111 to obtain a multiparthousing by means of a flange arrangement 87.

The design of the shut-off instrument 1 according to the invention makesit possible, with the option of using various different materials forthe instrument housing 3, shut-off element 23 with main body 28, supportdiscs 40, seal elements 34 as well as the slide valve stem 16 and theseal carrier 61, the seal arrangement 14 and the bearing arrangements15, to use it for media for all kinds even highly aggressive media andfrom low pressures up to high pressures and for a broad temperaturerange, e.g. between minus 50° and plus 300° C.

The shut-off instrument 1 according to the invention is alsocharacterised by the modular structure of the shut-off element 23,whereby the assembly and manufacture of the components is simplified,and there is an economic advantage as well as high manufacturingquality, which is particularly advantageous for serial production.

The simplification of assembly is achieved in that the componentsforming the shut-off element 23, such as the main body 28, sealingelements 34, support discs 40 and the required securing means 41 are fedthrough the flow channel 6 and can be assembled without expensiveassembly aids. This also makes maintenance or servicing simple as it ispossible to replace components in a straight forward manner.

In FIGS. 5 to 7 division possibilities are shown in a simplified formfor forming a multipart instrument housing 3. In order to connect thehousing parts forming the instrument housing 3, to simplify the drawingmethods know from the prior art, such as connecting flanges etc., arenot shown.

In FIG. 6 a division of the instrument housing 3 is shown in a divisionplane 91, in which the longitudinal middle axis 24 of the housingprojection 10 runs and is aligned perpendicular to the middle axis 25 ofthe flow channel 6.

In FIG. 5 in order to form a multipart shut-off element 3 a division isshown in a division plane 90, in which the longitudinal middle axis 24of the housing projection 10 and the middle axis 25 of the flow channel6 run together.

In FIG. 7 a division of the instrument housing 3 is shown, whereby themiddle axis 25 of the flow channel 6 runs in this division plane 92 andis aligned perpendicular to the longitudinal middle axis 24 of thehousing projection 10.

In FIGS. 8 and 9 a different design of the coupling arrangement 22between the main body 28 and the stem nut 19 is shown. According to thisdesign the stem nut 19 comprises a peripheral collar 94 at an endsection 93 facing the main body 28. The main body 28 is provided with acoupling mount 96 running over the entire thickness 95, which by itsdesign overlaps the collar 94 in parts, and thereby a moving connectionis obtained between the stem nut 19 and the main body 28 for adjustingthe main body 28 along the longitudinal middle axis 24 of the slidevalve stem 16, without a torque being transmitted from the stem nut 19to the main body 28.

In FIG. 10 a further embodiment of the guide arrangement 51 in theinstrument housing 3 for the shut-off element 23 is shown, whereby inthe illustration only a half section is shown. According to this designin the housing shaping 37 there are guide grooves 96 which run paralleland diametrically opposite the longitudinal middle axis 24, roughly inthe middle between the sealing surfaces 38. In the main body 28 guideelements 97 are secured projecting over the latter laterally andreaching into the guide grooves 96. Preferably, the guide elements 97are made from more than one piece and comprise a guide support element98 also secured in the main body 28 by the securing means 41 for theseal elements 34 and support discs 40, which guide support element isfor diverting the force, and also comprises a slide element 99 securedto the latter, e.g. made of a low friction material, in order to achievea smooth adjustment of the shut-off element 23 in the guide arrangement51.

Returning to FIG. 2 it should also be mentioned that a furtheradvantageous design of the shut-off instrument 1 according to theinvention is to divide the edge collars 35 of the seal elements 34provided on the sealing surfaces 38 in the region of the housing shaping37 for providing a seal by a groove running concentric to the externaldimension 36 and thereby form sealing lips 100, 101, whereby a bettersealing effect is achieved overall, but there is also the advantage thatfor the seal elements 34 a harder more resistant material with acorrespondingly long lifetime can be used.

In FIGS. 11 and 12 a further design of the shut-off instrument 1 isshown. According to the embodiment shown in these figures the main body28 of the shut-off element 23 is provided in one piece with the guideelements 94 with which the shut-off element 23 is guided linearly inguide grooves 96 arranged in the instrument housing 3 and in the housingprojection 10. Furthermore the main body 28 has slot-like mounts 102extending over the region of the securing means 41 from the mountingbore 45 for the slide valve stem 16 and symmetrically to thelongitudinal middle axis 24. Securing tabs 103 connected in one piecewith the stem nut 19 project into the latter, which are provided withbores 104, are connected by the securing means 41 to the main body 28 soas to be immobile. In this way a suitable connection and anchoring ofthe stem nut 19 to the shut-off element 23 is achieved for the assemblyof the shut-off element 23 inside the instrument housing 3.

The embodiment shown also comprises rivet bolts 105 as connecting means41 by means of which the components of the shut-off element 23,comprising the main body 28, the sealing elements 34 applied on bothsides thereof, and the support discs 40 are permanently connected.Preferably, the seal elements 34 comprise bores 106 for inserting thesealing collars 107 comprising the rivet bolts 105 and facing the mainbody 28, which engage in compatibly matching mounts 108, which in themain body 28 contain the bore 42 for feeding through the rivet bolts105, and produce a seal in the region of the bores 42 for the securingmeans.

As can also be taken from FIG. 11, in the region of the stem bushing 13in the housing neck extension 12 the slide valve stem 16 is providedwith the bearing collar 57, which in the embodiment shown is formedessentially from two annular surfaces 110 running towards one another atan angle to the longitudinal middle axis 24 in the form oftruncated-cone sleeve surfaces and projecting over a stem diameter 109.The thereby roughly V-shaped guide cross section of the bearing flange57 ensures, in connection with the bearing sleeve 59 arranged in thestem bushing 13 and the face seal ring 60, which are preferably made ofa highly resistant plastic with low sliding friction for bearingpurposes, a precise and long lasting bearing of the slide valve stem 16.The shaping of the bearing flange 57 together with the matchingprofiling of the bearing sleeve 59 and the face seal ring 60 produces aperfect radial and also axial bearing of the slide valve stem 16 in theregion of the stem bushing 13.

The bearing sleeve 59 facing the shut-off element 23 projects with anannular extension 111 over a ring-shaped end face 112 facing the slidevalve chamber 11 in the direction of the shut-off element 23 and thusforms a stop surface 113 for a ring-shaped end face 114 of the stem nut19 facing the latter, whereby the movement of the shut-off element 23into the open position, in which the flow cross section 8 is completelyopen, is restricted.

The seal carrier 61 inserted into the housing neck extension 12 by meansof the bayonet lock, already described in the preceding Figures,comprises in the region of the end face 70 of the housing neck extension12 at least two flanged noses 116 diametrically opposite thelongitudinal middle axis 24 and engaging in notch recesses 115, by whichthe seal carrier 61 is secured against rotation in the bore 62 of thehousing neck extension 11.

In FIGS. 13 and 14 a further design of the shut-off element 23 is shownin detail, in particular for shut-off instruments 1 with a greaternominal width, e.g. over 100 mm. In this design the main body 28 isformed essentially by two spaced apart, shaped wall discs 117, 118 formounting the seal elements 34 and the support discs 40, whereby the walldiscs 117, 118 form a hollow body 121 by means of wall sections 119 andspacing sleeves 120. Preferably, the wall discs 117, 118 together withthe wall sections 119 and spacer sleeves 120 and the laterallyprojecting guide elements 97 form a one-piece component.

At an end section 122 opposite the coupling arrangement 22 between thestem nut 19 and the main body 28 the main body 28 is provided with aflattened section 123, whereby the height 124 is smaller than thediameter 125 of a theoretical circle outline of the outer contour of themain body 28.

By means of this flattened section 123 the insertion of the main body 28into the instrument housing 3 and in particular the insertion of theguide elements 97 into the guide grooves 96 is made much easier duringthe assembly of the shut-off element 23 inside the instrument housing 3,whereby titling about the longitudinal axis 25 is necessary.

In order to ensure the required bearing and support for the sealelements 34 in the region of the main body 28 restricted by theflattened section 123, this section is installed before the assembly ofthe seal elements 34 and support discs 40, by means of a compensatingelement 127, completing the circular outline of the main body 28 which,can be coupled by a plug-and-socket connection 126 to the main body 28,in particular to the wall sections 119.

For form's sake it is pointed out that for a better understanding of thestructure of the shut-off instrument 1 the latter and its components arenot always drawn to scale and/or have been enlarged and/or reduced insize.

The objective forming the basis of the independent solutions of theinvention can be taken from the description.

Mainly the individual designs shown in detail in FIGS. 1, 2, 3, 4; 5; 6;7; 8, 9; 10; 11, 12; 13, 14 can form the subject matter of independentsolutions according to the invention. The objectives and solutionsrelating thereto can be taken from the detailed descriptions of saidfigures. List of Reference Numbers

-   1 Shut-off element 31 Coupling means-   2 Slide valve instrument 32 Support surface-   3 Instrument housing 33 Rib-   4 Connection element 34 Seal element-   5 Connection flange 35 Edge collar-   6 Flow channel 36 External dimension-   7 Arrow 37 Housing shaping-   8 Flow cross section 38 Sealing surface-   9 Nominal diameter 39 End face-   10 Housing extension 40 Support disc-   11 Slide valve chamber 41 Securing means-   12 Housing neck extension 42 Bore-   13 Stem bushing 43 Threaded bolt-   14 Seal arrangement 44 Threaded nut-   15 Bearing arrangement 45 Mounting bore-   16 Slide valve stem 46 Inner diameter-   17 Stem projection 47 Thread external diameter-   18 External thread 48 Distance-   19 Stem nut 49 Guide web-   20 Bore 50 Guide element-   21 Internal thread 51 Guide arrangement-   22 Coupling arrangement 52 Width-   23 Stop element 53 Recess-   24 Longitudinal middle axis 54 Guide sheet-   25 Middle axis 55 Double arrow-   26 Length 56 Guides-   27 Structure height 57 Bearing collar-   28 Main body 58 Bearing flange-   29 External dimension 59 Bearing sleeve-   30 Coupling groove 60 Face seal ring-   61 Seal carrier 93 End section-   62 Bore 94 Collar-   63 Grooves 95 Thickness-   64 O-ring 96 Guide groove-   65 O-ring 97 Guide element-   66 External circumference 98 Guide support element-   67 Mounting bore 99 Slide element-   68 Surface 100 Sealing lip-   69 Bearing bore 101 Sealing lip-   70 End face 102 Mount-   71 Recess 103 Securing tab-   72 Support surface 104 Bore-   73 Neck ring 105 Groove bolt-   74 Locking arrangement 106 Bore-   75 Spring arms 107 Sealing collar-   76 Locking mount 108 Mount-   77 Locking element 109 Stem diameter-   78 Mounting grooves 110 Annular surface-   79 Arrow 111 Annular extension-   80 Hand wheel 112 End face-   81 Stop arrangement 113 Stop surface-   82 End section 114 End face-   83 Detent ring 115 Notch recess-   84 Securing nut 116 Flanged nose-   85 Stop plane 117 Wall disc-   86 Lower side 118 Wall disc-   87 Flange arrangement 119 Wall section-   88 120 Spacer sleeves-   89 121 Hollow body-   90 Division plane 122 End section-   91 Division plane 123 Flattened section-   92 Division plane 124 Height-   125 Diameter-   126 Part connection-   127 Compensating element

1. Shut-off element for a shut-off instrument for a flow medium with adisc-shaped main body having at least one flattened section formed in aplane running perpendicular to a longitudinal middle axis and acompensating element arranged in the region of the at least oneflattened section and secured by a plug-and-socket connection, saiddisc-shaped main body being provided on opposite support surfaces withsoft seal sealing elements, and with a mounting bore penetrating thedisc-shaped main body for a slide valve stem , wherein on the supportsurfaces ribs projecting over their surfaces are arranged for forming astructure, for the engaged arrangement of the seal elements providedwith a compatible structure, and the seal elements on the disc-shapedmain body are secured by support discs arranged on opposite end faces ofthe seal elements by means of securing means penetrating the supportdiscs, seal elements and the disc-shaped main body in bores.
 2. Shut-offelement according to claim 1, wherein the disc-shaped main bodycomprises a hollow body formed by wall discs connected by wall sectionsand spacer sleeves.
 3. Shut-off element according to claim 1, whereinthe disc-shaped main body is provided with coupling grooves for mountingcoupling means of a stem nut (19).
 4. Shut-off element according toclaim 1, wherein the disc-shaped main body is provided with guideelements projecting over an external outline.
 5. Shut-off elementaccording to claim 4, wherein the guide elements are secured in thedisc-shaped main body.
 6. Shut-off element according to claim 4, whereinthe guide elements are connected in one piece with the disc-shaped mainbody.
 7. Shut-off element according to claim 4, wherein the sealingelements are connected to the support discs and the guide elements bysecuring means, arranged in a main body middle plane runningperpendicular to a longitudinal middle axis.
 8. Shut-off elementaccording to claim 1, wherein the sealing elements are penetrated by thesecuring means in bores, whereby the bores are pressure-tight with thesecuring means.
 9. Shut-off element according to claim 8, wherein arespective sealing collar is arranged surrounding the bore on thesealing element.
 10. Shut-off element according to claim 9, wherein tomount the sealing collar in the disc-shaped main body a mount isarranged for the sealing collar surrounding the bore.